<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
@keyframes jiazai
{
	from{ width:0%;}
	to{ width:100%;}
}
.box{width:500px; height:300px; background:#666; margin:150px auto; position:relative;}
.box1{height:30px; border:1px #000 solid;position:absolute; background:#000; top:250px; left:25px; border-radius:5px; animation:jiazai 5s; animation-fill-mode:forwards;}
</style>
</head>

<body>
	<div class="box">
    	<div class="box1"></div>
    </div>
</body>
</html>
